<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="./js/vue.js"></script>
</head>
<body>
<div id="app">
  <h2>当前计数:{{counter}}</h2>
  <button v-on:click="add">+</button>
  <button v-on:click="sub">-</button>
  <buttton @click="add"></buttton>
</div>

<script>
  const app = new Vue({
    el:'#app',
    data:{
      counter:0
    },
    methods:{
      add:function(){
        console.log('add被执行');
        this.counter++;
      },
      sub:function(){
        console.log('sub被执行');
        this.counter--;
      }
    }
  });
</script>
</body>
</html>
